The biology of
sialic acids has been an object of interest in many models of acquired and inherited skeletal muscle pathology. The present study focuses on the sialylation changes in mouse skeletal muscle after invasion by the parasitic nematode Trichinella spiralis (Owen, 1835). Asynchronous
infection with T. spiralis was induced in mice that were sacrificed at different time points of the muscle phase of the disease. The amounts of free
sialic acid, sialylated
glycoproteins and total
sialyltransferase activity were quantified. Histochemistry with
lectins specific for
sialic acid was performed in order to localise distribution of sialylated
glycoconjugates and to clarify the type of linkage of the
sialic acid residues on the
carbohydrate chains. Elevated intracellular accumulation of α-2,3- and α-2,6-sialylated
glycoconjugates was found only within the affected sarcoplasm of muscle fibres invaded by the parasite. The levels of free and
protein-bound
sialic acid were increased and the total
sialyltransferase activity was also elevated in the skeletal muscle tissue of animals with
trichinellosis. We suggest that the
biological significance of this phenomenon might be associated with securing integrity of the newly formed nurse cell within the surrounding healthy skeletal muscle tissue. The increased sialylation might inhibit the affected muscle cell contractility through decreased membrane ion gating, helping the parasite accommodation process.